Method oe and compound fob behoving from the barbels of fibeabms the



Patented Jan. 11, 1927.

UNITED- STATES PATENT OFFICE.

WILLIAM HOSKINS, OF CHICAGO, ILLINOIS.

METHOD OF AND COMPOUND FOR REMOVING FROM THE BARRELS OF FIREARMS THERESIDUES DEPOSITED BY LEAD BULLETS AND SMOKELESS AND SEMISMOKELESSPOWDER.

No Drawing.

This invention consists in a'novel method of and compound for removingfrom the barrels of firearms the residues left after shooting in thefirearms cartridges loaded with lead bullets and smokeless orsemismokeless powder. The removal of the residues left by black powdercartridges and by smokeless cartridges containing jacketed bulletspresents no particular difficulty atthe present time. The greatdifiiculty has however, been .experienced in the case of weapons,particularly those of small caliber, where the bullets are of lead andthe powder is either smokeless or semi-smokeless.

In such weapons, the residue is a'mixture ofgrease from the bulletlubricant, a considerable quantityof lead from the bullets, andpotassium chloride deposited by the primer. The latter is highlyhygroscopic and causes after-corrosion unless removed. The lead isinsoluble by ordinary cleansing agents and when mechanically mixed withthe grease makes it extremely diflicult toclean the surface.

I employ a compound or mixture containing a soft abrasive, hard enoughto cut lead but not hard enough to cut steel. My preferred compoundcontains tri-calcium-phosphate. With this I incorporate an emulsifyingagent,- such as'liquid soap, which will emulsify and break up thegrease, and water to dissolve the potassium chloride. In the use of thiscompound the barrel is scrubbed with one or two patches smeared with themixture of soap, water and a soft abrasive, and is then scrubbed with aseries 'of patches wet with water, or, in the alternative, water maybeeither run thru the barrel or pumped in and out of the barrel,

Application filed January 3, 1921. Serial No. 434,761.,

using a cleaning-rod after the manner. of a syringe. The barrel isfinally dried and covered with amoisture-excluding film of oil andgrease, in which condition it is perfectly safe from after corrosion. I

v I preferably mix the aqueous solution of soap andtri-calcium-phosphate to the consistency of cream, because the abrasivehas a tendency to settle out and in that condition. can readily beshaken up intothe mixture before using. Sucha cream may suitably beprepared by mixing 18 grams of trica'lcium-phosphate with 100 cos. of anaqueous solution containing 10% of potash soap. It must be understood,however, that this example is given by way'of illustration only and isnot intended to be limitative components.

I claim: 1. The herein described compound for removing from barrels offirearms the residue from lead bullets and smokeless or semisinceexcellent results are obtainedwith com-Z smokeless powder comprisingwater, an

emulsifying agent, and an abrasive of the hardness of.tri-calcium-phosphate.

2.1Th'e herein described method of removing from the barrels of firearmsthe residue from lead bullets and smokeless or semismokeless powder,which consists in simultaneously subjecting the residue to the action ofan abrasive hard enough to cut lead and not sufiiciently hard tomaterially cut the steel of the barrel, water, and an emulsifying agent,and subsequently washing and drying the barrel.

'WILL'IAM'HOSKINS.

